Is there the energy limit in the game?

Your energy limit will be constantly increasing throughout the whole game: you will have one energy point added to the your limit when you get a level-up twice. Just keep playing to increase the limit and get more energy points.
The game feature is that your energy stops growing upon reaching a certain limit. To get energy points beyond the limit in your game you can construct such objects as Energy Spring and Power Plant (that can be found in the Store → Extra) and supply them with goods. Please, note that your energy points can suddenly go down due to the fact that the energy source stops working. It gives you extra energy points for 24 hours when you load it with goods.